This invention provides a no-shear backrest assembly and an extending leg rest assembly working together to alleviate pressure and shear-related skin problems. Applicant's invention, utilizing mechanisms on the back, and running through the seat frame, offers floor-to-seat height versatility not existing in the prior art. Other inventions, such as U.S. Pat. No. 4,655,471 (1987) to Peek and U.S. Pat. No. 5,297,021 (1994) to Koerlin et al., contain complicated mechanisms under the seat frame, resulting in an overall floor-to-seat height greater than that of the original wheelchair. This greater seat height restricts accessibility to tables, desks, and transportation. These prior art attachments with their cams, scissor mechanisms, computer controlled actuators and such, are expensive, prohibiting acquisition by many would-be users.
It is an object of the invention that as the back section reclines, the leg rests articulate as well as extend away from the seat base. This action is essential to allow for the natural lengthening of the leg as it is reclining towards the horizontal position--this lengthening is an important factor for reducing shear.
It is also an object of the invention to lower the overall working height of a wheelchair with the said invention attached. Having the mechanical functions on the back, and running directly through the seat frame, allows this invention to provide flexibility concerning overall floor-to-seat height of wheelchairs to which it is attached, reducing accessibility restrictions.
It is further an object of the invention to reduce the weight of the reclining system. This is achieved through an efficient structural and engineering design. Weight reduction reduces wear on the wheelchair while increasing range and performance. This new invention allows for easy access to the wheelchair for service and maintenance without compromising structural integrity. Further benefits of this design include improved reliability through the substantial reduction of moving parts.
It is an additional object of this invention to provide leg rests that are easily removed and reattached for occupant transferring purposes. This invention holds substantial improvements over prior art, due in part, but not limited to, its utilization of a telescoping tubular component running through the seat frame. This through-frame technology eliminates prior arts' usage of various components, such as cams, actuators, linkages, scissor mechanisms, and other external devices, usually found under the seat, to recline the mechanism and activate the leg rests. This new through-frame technology is the basis for reducing the overall height and weight, while refining the entire reclining process.